At some point (of your choice) in the future, Fiddleford's radio will begin to spew static - regardless of whether its turned on or not. When Fiddleford touches it, electricity will course through his body; however, it will not cause him anything more than a moderate discomfort. As he watches, the markings on his body will start to spark, then activate one by one. Once they're all active and glowing, a synthesized voice will speak directly into his mind:

"Hello, Fiddleford. This isn't much, but I wanted to help where I could. Remember what I told you, okay?"

From this point on, he will be able to access all his new boons. If you wish, he can have instinctual knowledge of how to use the spells, or a robot in the arcade can explain for him!